cpu: Replace do_interrupt() by CPUClass::do_interrupt method

This removes a global per-target function and thus takes us one step
closer to compiling multiple targets into one executable.

It will also allow to override the interrupt handling for certain CPU
families.

Signed-off-by: Andreas Färber <afaerber@suse.de>

include/qom/cpu.h

@@ -44,6 +44,7 @@ typedef struct CPUState CPUState;
  * @class_by_name: Callback to map -cpu command line model name to an
  * instantiatable CPU type.
  * @reset: Callback to reset the #CPUState to its initial state.
+ * @do_interrupt: Callback for interrupt handling.
  * @vmsd: State description for migration.
  *
  * Represents a CPU family or model.
@@ -56,6 +57,7 @@ typedef struct CPUClass {
     ObjectClass *(*class_by_name)(const char *cpu_model);
 
     void (*reset)(CPUState *cpu);
+    void (*do_interrupt)(CPUState *cpu);
 
     const struct VMStateDescription *vmsd;
 } CPUClass;